Vibratory hand screed



March 30, 1943. c, JACKSON VIBRATORY HAND SCREED.

Filed July 21, 1941 I I INVENTOR. Co/"cud/ /ac/mvn Ci) MTOZEIL YS.

Patented Mar. 30, 1943 UNITED STATES PATENT OFF-ICE VIBRATORY HANDsominn Corwill Jackson, Ludington, Mich. Application July .21, 1941,Serial No. 403,312

7 Claims.

This invention relates to improvements in vibratory hand screeds.

The main objects of this invention are= First, to provide a vibratoryhand manipulated screed which is highly desirable for'the laying ofconcrete, factory floors, bridgedecks, sidewalks, and the like where lowslump or concrete having low water content is employed.

Second, to provide a structure of this char acter which is a completeunit, the prime mover being mounted on the screed and in manipulationconstitutes an integral part thereof.

Third, to provide a structure of this character in which an engine suchas an internal combustion engine may be used, it being mounted so thatobjectionable vibrations or shocks are not transmitted thereto and alsoto provide a structure in which the shocks or vibrations transmitted tothe workmen are minimized.

Fourth, to provide a structure embodying these advantages which is quitesimple and economical in structure and at the same time is durable andeflicient in use.

Objects relating to details and economies of the invention will appearfrom the description to follow. The invention is defined and pointed -11out in the claims.

A structure which is a preferred embodiment of the invention isillustrated in the accompanying drawing, in which:

Fig. 1 is a perspective view of a vibrating 1 hand manipulated screedembodying my invention.

Fig. 2 is a vertical transverse section on line 2-2 of Fig. 1illustrating certain details of the structure and the relation of theparts thereof, a

which is in general of channel section providing a front plate 2 ofsubstantial height and ascreed bottom 3. The rear plate 3| is of lessheight than the front plate 2 but is of sufficient height so that thescreed may be moved back and forth without becoming loaded up withconcrete. The braces 4 support the face plate.

Adjacent the center of the screed, in the embodiment illustrated, Iprovide a pair of vibrating element supporting brackets 5. These arebolted both to the bottom of the screed and to the front plate, see Fig.2. The vibrating element designated generally by the numeralfi isprovided with a rotor shaft I having a counterbalancing weight 9thereon, the shaft 1 being supported in the casing 8 of the vibratingelement. i i I The flexible'driving shaft I0 for the unbalanced rotor ispowered from a' prime mover, preferably mounted as hereinafterdescribed. At each end of the screed I mount a pairof brackets IIinspaced relation and provided with opposed stud-like anchoring elementsl2. The flexible support members 13 which may suitably and preferablybelengths of heavy-walled steam hose are telescoped with these studmem-' bers l2 and secured thereto by clamps 14. These support membersare arranged in spaced pairs and are provided intermediate their endswith cross pieces l6 secured to the flexible support members by theclamps I5. t The reinforcing tubes 2| are arranged Within the flexiblesupport members I 3 toprevent their! collapsing under the stress of theclamps l5.

The handles l9 are bifurcated or provided with spaced arms l8 which aresecured to the cross piecesby means of the U-bolts or clamps H. Thehandles are provided with handle bars 20 at their outer ends, the'armsbeing arrangedin angular relation to the shaft portion of the handles sothat the handle bar is at the proper height for grasping. 'Thisattachment of the handles provides for stability in manipulation andminimizes the efforts'of th'e'op erator inkeeping the screedinupright'position'. i a

I The prime mover'22, desirably an internal combustion engine ofsuitable horse power, is mounted on the cross pieces of one pair offlexible supports between the arms "of'the handle at that end of thescreed. The shaft l0'is 'directly connected to the engine'.' Arelatively small one-cylinder internal combustion engine has been foundto be quite suitable. 1 r In use, the operators grasp the handles andmanipulate the screed over the work. Due to the employment oftheflexible tubularsupport mom bore, the vibrations of the screedare'largely dampened from the handles" and also from-the engine Thetubular form of flexible support members provides sufficient rigidity inthe connection from the handles to the screed so that the screed may bemanipulated in any direction, longitudinally or forward and back, withno objectionable sensation of slackness or lost. motion on the part ofthe operators, at the same time the shocks and vibrations areefiectively dampened from the motor or prime mover and the handles.

The foregoing machine is used extremely efiectively in the laying offactory floors, bridge decks and other applications where low slumpconcrete is employed. It may be transported readily to any desiredlocation and placed in operation with a minimum of difiiculty and littleexpenditure of time.

An embodiment of the invention which incorporates the principles of theinvention in a high-'- ly desirable manner has been illustrated anddescribed. It should be understood that the foregoing terminology isused descriptively-rather than in a limiting sense, and with fullintention to include equivalents of the features shown and described,within the scope of the following claims.

Having thus described-my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a structure of the class described, the combination of anelongated screed, a vibrating element mounted thereon invibration-transmitting relation thereto, brackets disposed on saidscreed adjacent the ends thereof in opposed spaced pairs and providedwith stud-like members, pairs of flexible tubular support memberstelescopingly engaged with said studs and clamped thereon, cross piecesclamped upon said support members intermediate the ends thereof, saidsupport members being internally reinforced to prevent collapsingthereof by the clamping means, bifurcated handles, the arms of which aresecured to said cross pieces, a prime mover mounted on the cross piecesof one pair of supports between the arms of i the handle securedthereto, and a flexible driving connection for said prime mover to saidvibrating element, said flexible supports acting to dampen thevibrations from said screed to said handles and prime mover.

2. In a structure of the class described, the combination of anelongated screed, a vibrating element mounted thereon invibration-transmitting relation thereto, brackets disposed on saidscreed adjacent the ends thereof in opposed spaced pairs and providedwith stud-like members, pairs of flexible tubular support memberstelescopingly engaged with said studs and clamped thereon, cross piecesclamped upon said support members intermediate the ends thereof, saidsupport members being internally reinforced to prevent collapsingthereof by 'the clamping means, and bifurcated handles, the arms ofwhich are secured to said cross pieces, said flexible supports acting todampen the vibrations from. said screed to said handles.

3. In a structure of the class described, the combination of anelongated screed, a vibrating element mounted thereon invibration-transmitting relation thereto, brackets disposed on saidthereof, bifurcated handles, the arms of which are secured to said crosspieces, a prime mover mounted on the cross pieces of one pair ofsupports between the arms of the handle secured thereto, and a flexibledriving connection for said prime mover to said vibrating element, saidflexible supports acting to dampen the vibrations from said screed tosaid handles and prime mover.

4. In a structure of the class described, the combination of anelongated screed, a vibrating element mounted thereon invibration-transmitting relation thereto, brackets disposed on saidscreed adjacent the ends thereof in spaced pairs,

' pairs of flexible support members secured at their ends to saidbrackets, cross pieces mounted on 'said flexible supports intermediatethe ends thereof, and bifurcated handles, the arms of which are securedto said cross pieces, said flexible supports acting to dampen thevibrations from said screed to said handles.

5. In a structure of the class described, the combination of anelongated screed, a vibrating element mounted thereon invibration-transmitting relation thereto, brackets disposed on saidscreed adjacent the ends thereof in opposed spaced pairs and providedwith stud-like members, flexible tubular support members telescopinglyengaged with said studs and clamped thereon, handles secured to saidflexible supports intermediate the ends thereof, a prime mover mountedon one of said flexible supports intermediate the ends thereof, and aflexible driving connection for said prime mover to said vibratingelement, said flexible supports acting to dampen the vibrations fromsaid screed to said handles and prime mover.

6. In a structure of the class described, the combination of anelongated screed, a rotor provided with an unbalancing weight mounted onsaid screed medially thereof, flexible support members disposed inparallel relation to the screed adjacent the ends thereof and eachsupported thereon from its opposite ends, said supports being arrangedin spaced pairs and provided with intermediately disposed cross members,handles secured to said cross members, and a prime mover for said rotorhaving flexible drive connection thereto and mounted on and supportedsubstantially in its entirety by one pair of said support memberswhereby the vibrations from the screed to the handles and prime moverare dampened.

7. In a hand screed, the combination of an elongated screed memberhaving vibrating means mounted thereon, flexible tubular supports eachsupported from its opposite ends on said screed adjacent the endsthereof and in parallel relation thereto, handle secured to saidsupports intermediate the ends thereof, and a prime mover for saidvibrating element mounted on and supported substantially in its entiretyby one of said supports and having flexible drive shaft connections tosaid vibrating element, said flexible supports acting to dampen thevibratory impulses of said screed in relation to said handles and primemover.

CORWILL JACKSON.

